Waves, Sound and Light - Topic 2, Electromagnetic Waves

Question 1

Name four properties common to all electromagnetic waves

Answer 1

• Electromagnetic waves carry transverse vibrations, vibrations in electrical and magnetic fields, not vibrating particles.
• Electromagnetic waves do not need matter to travel through, they can travel through empty space (a vacuum).
• In a vacuum, all electromagnetic waves travel at approximately 3x10*8 m/s, the fastest speed possible.
• When electromagnetic waves travel through matter (for example light through air or glass), they travel a slower than this, but rarely less than half as fast as in a vacuum. The value for light travelling through an optical fibre, for example, is taken as 2x10*8 m/s.

Question 2

Name one type of electromagnetic radiation which causes sun-tan

Answer 2

Ultra Violet (UV)

Question 3

Name one type of electromagnetic radiation which is used for satellite communication

Answer 3

Microwave

Question 4

Name one type of electromagnetic radiation which passes through a thin sheet of lead

Answer 4

Gamma rays

Question 5

Name one type of electromagnetic radiation which is used to take photographs in haze

Answer 5

Visible light